A bit more about zinc

gdenby

After yesterday's thread about using zinc coated hardware for homemade Egg accessories, I decided to read around a bit about "fume fever." Most of what I found referred to people welding galvanized metal. One interesting note was that the mix for galvanizing usually includes some lead. I've never seen anything galvanized used for cooking, so I figure that's not a big problem. Curiously, a similar thread was on the BBQ Forum yesterday. A follow-up today stated that the "autocombustion" temperature for zinc was a mere 860 F. So, it would follow that the zinc coating would end up sooner or later burning in the Egg. Makes me want to toss a bolt on some burning lump just to see if it flares.

gdenby

fishlessman

im probably the only egger to do this, but ive melted lead in my egg to pour into fishing weight molds. you really need to be in a confined area, or be breathing directly from the top vent to get metal fever which is highly unlikely, even at a mere 860 degrees. if your welding on galvey, just a hose running behind you clipped to your belt and to a small face mask is enough that the galvey fumes disperse enough. beware that if you have eaten beans, there are other fumes to worry about

gdenby

Good to know. I wondered if opening the Egg would let out a cloud of noxious gas, depending on what sort of hardware was inside. Evidently it would be sufficiently diffused.

Have you ever burnt zinc? Other than sparks from various metals, and some magnesium shavings, I've never encountered burning metals.

gdenby

stike

well... hate to beat a dead horse, but it seems to keep rising from the grave. hahaha

first, fume fever from zinc is not lethal. the only warning against even being in the presence of zinc fumes is that it be limited to 15 minutes max. The only requirement for working with it is "adequate ventilation".

second, you create far more dangerous 'fumes' of carbon dioxide EVERY time you cook, and at any temp. where is the concern for that? i submit that zinc concerns are misplaced.

people are afraid to fly, but not to drive. one is far safer, but it is feared because it is not understood. that applies to pretty much everything. we fear what we don't understand.

people seem to dial in on zinc because "they heard it from a guy". careful reading of any of the material data safety sheets says similar things for stainless, copper and aluminum. so if zinc is somehow dangerous, then i would ask how someone can automatically assume the others are safe.

truth is, they ALL are safe.

a person can't get good info about this from a barbecue forum (including from me on this forum). if someone has concerns, they should take the time to research it themselves.

fumes do not occur at 800 degrees. you need much higher temps.

stike

every time you open your egg you already DO let out toxic fumes. funny how no one worries about that. because it is safe under normal conditions. the egg, in a poorly ventilated area is a death machine (any charcoal cooker, propane heater, etc. is).

the fact that you haven't died yet means your egg is properly ventilated. even if you could get the zinc to turn to gas (which you couldn't, even tossing the bolts in).

gdenby

I'll take a slightly different position. All heated metals are bad to breathe near, but in most cases are a problem only over a long term. During winter, in old kitchens like mine without exhaust fans, the accumulated vapors from cooking and baking can make the air as poor as if you lived down wind from a smelter. So, I keep a window cracked, and any more do my high temperature cooking in the Egg.

gdenby

fishlessman

burnt all types of weird metals, ive got one that i dont remember what its called, lit the saw on fire while cutting it under water. a bottle cap full in a pail of water would explode if you tossed a match near it and vaporize a couple gallons instantantly, made magnesium shaveings look safe. i think i still have a piece of that around, it was something that sounded like ferrylium but cant remember exactly what it was called. first time i lit the bucket, the white flame hit the ceiling about 30 feet up and knocked me flat onto my back. being a kid, i had to do it again, but outside.

stike

i guess all i'm saying is that the argument that zinc bolts used in the egg will off gas and kill you is a myth. all good myths have an element of truth in them, and that is why they persist.

zinc bolts on a home-made raised grid cannot be gotten to the temps required to gas. even if they DID, and you breathed them in, you'd be fine. EVEN if somehow you smelted a grocery bag full of them and gave yourself fume fever, you'd already be dead from the carbon monoxide and smoke inhalation.

it is an irrational fear. the most persistent kind.

Jeffersonian

As it so happens, I'm working on a job right now to update the control systems at a local zinc processing plant. I'm going to sit down with one of the guys there and ask him what sort of problems it can cause and what they do to abate it.

stike

i bet they run for their lives, screaming, with their arms flapping over their head.

Rusty Rooster

Sounds like we need to send this idea to Mythbusters. LOL

Jeffersonian

They're kinda a squirrely bunch there...they do that even when the plumes of murderous zinc aren't roiling out of the cauldrons :P

Here's the MSD Sheet on ZINC

It looks like you don't want to make a habit of breathing it, but it's not terribly toxic and only melts at temps well over 700*F.

Jeffersonian

Sounds like sodium...nasty stuff, that.

stike

it isn't dangerous at all. fume fever from zinc is short-lived, self limiting, and non-fatal. i still maintain that a close understanding of it (just from the info on the safety shhet itself) proves it's impossible to have any dangerous issue with zinc bolts in an egg.

gdenby

Ah, that brought back a memory. A kid I knew had a chemist dad. Showed me me a lump of sodium. Said "Watch what happens," and tossed it into the toilet and flushed. Blooey! Needless to say, the folks were not happy to replace their drain pipe.

gdenby

Grandpas Grub

I was observing temps in the egg...

Dome was 450° - 1" above and below the gasket was 360° (read on the ceramics). I had the cast iron dome sitting on the grid and it was 680° (6 inches away from the edge of the gasket). I was thinking a large cast iron object (like a dutch oven) on the grid might damage the felt gasket.

With that said most of my cast iron cooks are at 330° at grid level or less when using the dutch oven.

GG

Jeffersonian

I'd tend to agree, plus the amount of zinc on four galvanized bolts is tiny. If you're really worried about it, use stainless bolts.

stike

and if you are worried about rust under your car, you should pay extra for undercoating!

(both are uneccessary... )

[Deleted User]

In my post the other day, I quoted the guy who writes for popular Science who said you can melt zinc without the off-gassing (zinc oxide). The bad stuff is released when it's closer to boiling which is over 1600 degrees Farenheit, 907C. Even when I tried to see how hot it would get (and I fried my gasket) I couldn't get the Egg anywhere near that hot.[url][/url]